Rapid climatic changes during the Greenland stadial 1 (Younger Dryas) to early Holocene transition on the Norwegian Barents Sea coast

Abstract

A pollen‐based quantitative climate reconstruction from a lake‐sediment core on the Norwegian Barents Sea coast provides insights about climatic change over the Greenland stadial 1 (GS‐1) to early‐Holocene transition. GS‐1 was characterized by low July mean temperatures (c. 6.0°C) and dry conditions probably resembling modern arctic deserts. The increase in July mean temperatures to the Holocene level (10.0–12.0°C) took place in a two‐step pattern interrupted by a short cool period with July mean temperatures of c. 8.0°C during the early Preboreal at c. 11450–11200 cal. yr BP. The reconstruction also suggests two other early‐Holocene coolings of c. 1.5°C, dating to 10900–10800 cal. yr BP and 10400–10200 cal. yr BP, synchronously with short‐term decreases in δ18O values in the Greenland ice cores. These results reflect the highly unstable nature of the early‐Holocene climate in northernmost Fennoscandia. Apart from the cooling at 10900–10800 cal. yr BP, the reconstructed cold events correlate with fluxes of fresh water to the North Atlantic and related reductions of North Atlantic deep‐water formation, suggesting that the rapid climate changes resulted from the dynamics of the North Atlantic thermohaline circulation and oceanic energy transport during the GS‐1 to early‐Holocene transition.